Development of a test rig for the study of gas-based nanofluids

Nanofluids, comprising nanoparticles suspended in conventional heat transfer fluids, reveal significant increase in thermal conductivity and convective heat transfer. This research article investigates the application of gas-based nanofluid in concentrated solar power plant (CSP) technologies. Traditional heat transfer fluids, like synthetic oil and molten salts, present limitations such as flammability toxicity and operational temperature. In contrast, gas-based nanofluids show improved thermal and optical properties making them a promising alternative for high-temperature solar applications. In this research, an innovative open circuit test bench operating with gas-based nanofluid as heat transfer fluid is presented. Particularly, an open circuit test bench was designed for experimental analysis, incorporating a solar simulator to control sunlight intensity in a laboratory setting. A theoretical model was developed based on solar simulator irradiance, and numerical analysis was conducted. Nanofluids containing CuO nanoparticles exhibited an optimal extinction distance within a few centimeters at a volume concentration of 0.50%. Besides, also the temperature increase achievable with this concentration of nanoparticles is compatible with various thermal and electrical power generation applications.